I am relatively new to R, but this is the first time I have had to deal with date conversions. I read in my data from a CSV (using read.table()), but I shorted the data to highlight my issue. When read into R, the Date field is character.
Simply, most of my dates get coerced correctly, except for a few instances. The example below will hopefully show you what is going on.
# my attempt to coerce the date -- uses the stringr package
prods.all$Date2 <- as.Date(str_sub(prods.all$Date, 1,
str_locate(prods.all$Date, " ")[1]-1),
"%m/%d/%Y")
# grab two rows to highlight my issue
temp <- prods.all[c(1925:1926), c(1,8)]
> temp
Date Date2
1925 10/9/2009 0:00:00 2009-10-09
1926 10/15/2009 0:00:00 0200-10-15
As you can see, the year of some of the dates is inaccurate. The pattern seems to occur when the day is double digit.
I have looked through a couple of books and tried to Google a better way, but everything seems to suggest that my data are not formatted correctly on input.
Given how powerful R is, I figure that there is a very easy way to force my column to be valid dates and that I am overlooking a very obvious solution.
Any help you can provide will be greatly appreciated.
You may be overcomplicating things, is there any reason you need the stringr package?
df <- data.frame(Date = c("10/9/2009 0:00:00", "10/15/2009 0:00:00"))
as.Date(df$Date, "%m/%d/%Y %H:%M:%S")
[1] "2009-10-09" "2009-10-15"
More generally and if you need the time component as well, use strptime:
strptime(df$Date, "%m/%d/%Y %H:%M:%S")
I'm guessing at what your actual data might look at from the partial results you give.
library(lubridate)
if your date format is like this '04/24/2017 05:35:00'then change it like below
prods.all$Date2<-gsub("/","-",prods.all$Date2)
then change the date format
parse_date_time(prods.all$Date2, orders="mdy hms")
The easiest way is to use lubridate:
library(lubridate)
prods.all$Date2 <- mdy(prods.all$Date2)
This function automatically returns objects of class POSIXct and will work with either factors or characters.
Source: Stackoverflow.com